Scottish Labour is on the brink of civil war after a leaked recording of interim leader Alex Rowley led to accusations of a long-term plot to oust Kezia Dugdale and replace her with Richard Leonard.

In an extraordinary attack, Labour MSP Jackie Baillie accused Mr Rowley of “hypocrisy” and a “complete betrayal” of the party.

In the recording, reportedly made in Brighton at the Labour conference and obtained by the Sun, Mr Rowley says he has backed Mr Leonard to become leader “for some time now” and that he “didn’t believe Kezia would be there in 2021” to lead the party into the next Scottish election.

Mr Rowley publicly pledged to remain neutral in the leadership race between Anas Sarwar and Mr Leonard, who is seen as the preferred candidate of the pro-Corbyn left of Labour.

The interim Scottish Labour leader told the BBC: “I haven’t come out for any candidate. I’ve remained neutral.”

Mr Rowley reportedly made his remarks in a queue for a fringe event in Brighton hosted by Momentum, the campaign group backing Mr Corbyn’s leadership.

Speaking to a man who describes himself as a politics and theater student from Glasgow and his female companion, Mr Rowley says: “Although I’m neutral in the leadership I also believe that Richard Leonard has everything that we need to win in 2021. I really do.

“So when, to our surprise, the job became vacant, it just seemed to me that from a left perspective the person that was most suited to do that job would be Richard Leonard.”

He went on: “For some time now I’ve thought he [Richard Leonard] was the best candidate. And most people within the left in Scotland I think thought likewise… our view was that Richard was the best person and therefore we should go with that plan.”

Responding to the leak, Ms Baillie said: “This hypocrisy is extremely concerning given Alex’s public commitment to remain neutral during the leadership contest.

“Once again, the bitter divisions within Labour are never far from the surface.

“As we’ve seen in recent days, Labour cannot be trusted on basic matters such as protecting Scotland’s single market membership – it is clear that they are more interested in settling old scores than focussing on the real issues facing the country.”

A Scottish Labour spokesman said: “Alex was having what he believed to be a private conversation with a student and a political activist. He has not and will not publicly back a candidate.

“He has no intention of relinquishing his role as interim leader of the Labour Party in Scotland until after the current leadership contest is over.”